This invention relates generally to modular conveyor belts hingedly linked by hinge pins and, more particularly, to non-integral attachments in such conveyor belts.
Conveyor belts are widely used in many industries to transport articles. In the food and beverage industries, modular plastic belts, or chains, are often used because of their cleanability and their ability to operate with little lubrication. The modular belts are generally constructed of a plurality of rows of belt modules arranged side by side to form a belt row. The modules silo include hinge elements at each end. The hinge elements of consecutive rows are interleaved and interconnected by hinge pins to construct a conveyor belt of any desired length and width.
Usually, these belts form generally flat-top article-conveying surfaces. But some applications require accessories that deviate from the flat article-conveying surface. Sideguards, flights, rollers, holddown tabs, guides, and various inserts are just some examples of accessories added to belts to perform various functions. Flights that extend across the width of a belt at regular intervals are often used in transporting articles up or down inclined paths. Often the flights are integrally formed coextensive in width with an interleaved module to form a flighted module. Regularly spaced belt rows are then formed entirely of flighted modules to construct a belt with flights extending across the width of the belt at regular intervals.
As long as the integral flights do not extend beyond the sides of the module and do not include any complicated contours or openings, relatively simple molds can be machined to form flighted modules in an injection molding process. Otherwise, the mold can be expensive and difficult to use properly.
One shortcoming associated with integral flighted modules is that they must be made in a separate mold and represented by a separate part number from those of the standard non-flighted belt modules with which they are interconnected to form a conveyor belt. Another shortcoming is that, once a flight is damaged, the entire flighted module must be replaced.
To solve this last problem, detachable flights have been used. But these usually require attachment to a specially designed base module with a specially designed receptacle for the flight. Or the flight must be attached to some extra retainer, such as fastener hardware that could come loose and contaminate the conveyed product.
To overcome these shortcomings, there is a need for a conveyor belt that accepts accessory attachments of various configurations, including complicated topographies, without necessarily requiring special receptacle modules and without requiring additional fastening hardware.
This need and others are satisfied by a conveyor belt and attachment element having features of the invention. The conveyor belt is constructed of a plurality of belt modules and hinge pins arranged in rows. Each row includes one or more side-by-side belt modules linked at leading and trailing ends to another row by hinge pins. The resulting belt has first and second, for example, top and bottom, outer surfaces. At least some of the rows include blocking structure and one or more receptacles opening onto an outer belt surface. Blocking surfaces formed in the belt modules form at least part of the boundaries, or walls, of the receptacles. An attachment element includes a contact member and a set of appendages. The appendages, which are preferably hook-shaped, extend outward from the attachment element. When appendages are inserted in the corresponding receptacles and the contact member is in contact with the blocking structure of the row, the blocking surfaces constrain the appendages to keep the attachment element in place in a conveying condition of the conveyor belt. This dual interaction of the appendages with the blocking surfaces of the receptacles and the contact member with the blocking structure locks the attachment assembly in place. In the conveying condition, each row of the belt generally defines a plane. In an assembly condition, one or more rows deviate from the planar configuration. The assembly condition can be achieved, for example, by removing a hinge pin from one end of a row of side-by-side modules. In the assembly condition, the dual interaction is absent and the appendages can be inserted into or removed from the receptacles.
In one version of the conveyor belt and attachment element, the contact member on the attachment is realized by one or more of a second set of appendages alternately arranged along the attachment element with the first-mentioned set. Each set is differently directed and can be inserted into or removed from the receptacles only in the assembly condition of a belt row.
In another version, the contact member is a hooked-shaped appendage that contacts a hinge pin""s lateral surface, which serves as blocking structure and acts in tandem with blocking surfaces bounding the associated receptacles in the belt row to keep the appendages firmly in place.
In still another version, the contact member is a flange extending outward from the attachment member along its base. The first or second outer surface of the belt row serves as the blocking structure. In the assembly condition of the belt, the flange is out of contact with the blocking structure, and the attachment member can be inserted into and removed from the belt. In the conveying condition, the flange contacts the outer belt surface and, together with the interaction of the blocking surfaces of the receptacles with the appendages, keeps the attachment member in place.
The appendages, in a preferred version, include a shank portion extending from the attachment element with a distal hook portion angling away from the shank portion. The angle at which the hook portion extends from the shank portion determines the insertion angle at which the attachment element is oriented for its appendages to be inserted into and removed from the receptacles.
These various versions of attachment schemes allow for a variety of attachment elements with accessory portions of various functions and topographies to be incorporated into standard belt modules. The attachment elements can be tailored to the application or replaced when they are damaged or wear out without replacing the entire belt. The dual interaction of the appendages with the blocking surfaces and of the contact member with the blocking structure ensures a firm connection of the attachment element to the belt without extra fasteners that could come loose and contaminate conveyed products.